module.exports=(totalSize,req,res)=>{
	const range=req.headers['range'];
	if(!range){
		return {code:200}
	}
	const sizes=range.match(/bytes=(\d*)-(\d*)/);
	const end=sizes[2]||totalSize-1;
	const start=sizes[1]||totalSize-end;

	if(start>end||start<0||end>totalSize){
		return {code:200}
	}

	res.setHeader('Accept-Ranges','bytes');
	res.setHeader('Content-Range',`bytes${start}-${end}/${totalSize}`);
	res.setHeader('Content-length',end-start);
	return {
		code:206,
		start:parseInt(start),
		end:parseInt(end)
	}
}